Toll charge computer



10 Sheets-Sheet 1 Jan. 5, 1965 F. A. MORRIS ETAL TOLL CHARGE COMPUTER Original Filed Feb. 11, 1957 Jan. 5, 1965 F. A. MORRIS ETAL Tou. CHARGE COMPUTER l0 Sheets-Sheet 2 Original Filed Feb. 11, 1957 Jan.

F. A. MORRIS ETAL TOLL CHARGE COMPUTER Original Filed Feb. ll, 1957 10 Sheets-Sheet 5 Jan. 5, 1965 F. A. MORRIS ETAL 3,164,577

Tou. CHARGE COMPUTER Original Filed Feb. 11, 195'? 10 Sheets-Sheet 4 /apsed Time Counter- 600 TENS MINUTES COU/VT/VG CHAIN-400 Jan. 5, 1965 F. A. MORRIS ETAL 3,164,677

TOLL CHARGE COMPUTER Griginal Filed Feb. 11. 1957 10 Sheets-Sheet 5 Elapsed Time Counterv600 are asaJ

Jan. 5, 1965 F. A. MORRIS ETAL 3,154,677

TOLL CHARGE COMPUTER original Filed Feb. 11, 1957 1o sheets-sheet e Elapsed Time Coun/er- 600 ssl) UNITS MINUTES COUNT/NG RING 500 FIG. 6

Jan. 5, 1965 F. A. MoRRls-ETAL 3,164,677

TOLL CHARGE COMPUTER Original Filed Feb. ll, 195'?A l0 Sheets-Sheet '7 BASE r/ME couv/TER-roo FIG. 7

Cost Computer-239 Jan. 5, 1965 F. A. MORRIS ETAL 3,164,677

v TOLL CHARGE COMPUTER original Filed Feb. 11, 1 95'1 1o sheets-snaai s FIG. 8

"6J Cost Computer 239 TEN Cta/ITS COUNTER-725 Jan. 5, 1965 F. A. MoRRls ETAL 3,164,677

TOLL CHARGE COMPUTER original Filed Feb. 11, 195'? 1Q sheets-sheet 9 Cost Computer -239 UNITS CENTS COUNTER-900 Jan. 5, 1965 F. A.' MQR'Rls ETAL 35164677 Tou. CHARGE COMPUTER original Filed Feb. 11. 1957 I v v 1b sheets-sheet 1o sa PREPARE 7U READ RESET F' l I /032N T, I Fl :M062 /0/ I e E +.o loa! Mgg Y 'loss /o/Ju meu-9 $1065 Uw/4 T i 5066 ,05: lm/ff C4,/0/6 /042\,; H /0/9; i Mfr-f "'0" FIG. l0

2 1f/044 /ola "H gas ' #VWL/045 Cosi Computer-239 q K9 AFIG. /2

FIGJ F/GZ F/G'. FIG. F/G. Fla 3 4 5 6 975) Fla FIG. F/G. FIG.

v UNITS DOLLARS COUNTER-905 FIG. ll

terval, and the rate structure means also primes the counting rings and chains to manifestations representing the initial charge which is to be assessed for this base time period. A Y v Following the priming of this rate information into the cost computer, the magnetic tape in the trunk recorder is advanced so that the group of one minute duration pulses is transmitted to the cost computer and, in parallel therewith, to an elapsed time counter including a units minutes counting ring anda tens minutes counting chain. These Vpulses advance the elapsed time counter to manifestation representing the total number of pulses received from the trunk recorder to establish the length of the toll call. The elapsed time pulses applied to the cost computer first operate the base time counter so that a selected number thereof are rendered ineffective to advance the cents and dollars counting circuits, thereby effectively subtracting the base time interval from the duration data. After a number of signals or pulses representing the length of the base time interval have been received, the base time counter renders the live cents counting ring responsive to the remainder of the group of duration signals so that the live cents counting ring, the tens cents counting ring, and the dollars counting chain are advanced step-by-step in accordance with the remaining signals or pulses transmitted from the trunk recorder, thereby to advance the original manifestation representing the initial charge to a manifestation representing the total charge, which total charge comprises the sum of the initial charge and the charge increments which have been added for the overtime intervals.

Following the completion of the establishment of the charge to be assessed for the toll call, a switching means in a recording control circuit is rendered effective to sequentially connect the counting chains and rings in the elapsed time counter and the cost computer to the recorder so that a permanent record of the duration of the call and the monetary charge to be assessed therefor are provided. Following the completion of the recording of this information, the elapsed time counter and the cost computer are cleared, and the data pertaining to the next toll call recorded on the seized trunk recorder is transmitted, thereby to establish the duration of this call and the charge to be assessed therefor.

Following the completion of the transmission of all of the information stored in the rst trunk recorder, the playback control circuit is operated to advance the switching means associated therewith to seize the next trunk recorder. Incident to seizing this next trunk recorder, the cost computer is again provided with a rate structure which is applicable to the areas between which the calls are extended whose data is stored in this next seized trunk recorder. In a similar manner, the items of information pertaining to the toll calls stored on all of the trunk recorders to which the switching means in the playback control circuit has access are played vback to provide printed or perforated records including the durations of the calls and the charges to be assessed therefor.

Other objects and advantages of the present invention will become apparent from the ensuing description of an illustrative embodiment thereof in the course of which reference is made to the accompanying drawings in which:

FIGS. 1 and 2 are a one-wire block diagram of an automatic toll ticketing system embodying the present invention which is shown in conjunction with a conventional automatic telephone system;

FIG. 3 is a fragmentary schematic drawing of components of the automatic toll ticketing system which are used in conjunction with the cost calculating means of the present invention;

FIGS. 4-6 form a schematic diagram of an elapsed time counter associated with the cost computer;

FIGS. 7-10 form a schematic diagram of the cost computer;

FIG. 11 is a block diagram illustrating the manner in which FIGS. 3-10 are positioned adjacent each other to form avschernatic diagram of the automatic toll ticketing system including the elapsed time counter and the cost computer; and

FIG. 12 is a block diagram illustrating the manner in which FIGS. 1 and 2 are positioned adjacent each other to form a complete block diagram of the system.

Referring now to FIGS. 1 and 2 of the drawings, therein is illustrated a block diagram of an automatic toll ticketing system of which the computing means of the present invention forms a part and which is of the type shown and described in detail in the above identified Morris et al. patent. This system includes a substation A located in a local exchange 107, an additional substation B which is located in the exchange 107, and a plurality of remote substations C and D which are located in areas geographically remote from the exchange 107 and to which toll calls requiring the automatic collection and storage of information can be extended.

In extending a local call for which toll data is not to be collected, going olf-hook at the calling substation A completes the calling loop circuit over a line 110 to a line circuit 111, the operation of which places an allotter in operation by supplying start ground to a common start conductor 115g. The allotter 115 searches for an idle link, such as a link 112 including a finder 113 and a selector 114, and operates the finder 113 in the link 112 to search for and seize the line circuit 111, thereby extending the calling loop circuit to the selector 114.

In response to the receipt of dial tone, the subscriber at the substation A dials the digits forming the designation of the local substation B so that the selector 114 and a connector 116 respond to these signals to extend a connection to a line circuit 117 which is connected to the called substation B over a line 118. In response Vto the receipt of answering supervisory signals, the calling loop circuit is cut through between the substations A and B to permit conversation. When the connection is released, the connector 116 and the link 112 are released to permit their subsequent use in extending telephone connections.

When a call is to be extended from the local substation A to a remote substation C, which may comprise a short or long haul toll call, the call is initiated by going offhook at the calling substation A to place the allotter 115 in operation, as described above, so that an idle link, such as the link 112, is associated with the line circuit 111 and the selector 114 therein is conditioned to receive dial impulses. In order to seize the automatic data collecting and storing equipment forming a part of the automatic toll ticketing system, the lirst digit dialed at the substation A in extending the toll call is an access digit which varies in accordance with the remote area in which the called substation A is located. In response to receiving the dialed access digit, the selector 114 advances its wipers to the proper level and searches over the contact multiples in the selected level to seize an idle trunk circuit extending to the desired remote area. Assuming that the call is to be extended to the substation C, an idle one-way trunk circuit 119 is seized over a conductor 1196i to prepare this circuit for repeating switch directing signals over a conductor 120 to a four-digit remote automatic exchange 10S to which the substation C is connected by a conductor 121. Incident to seizure, the one-way trunk circuit 119 prepares circuits for recording data pertaining to the toll call in a trunk recorder which is individual to the trunk circuit 119.

Alternatively, if the call is to be extended to the substation D in a different geographic area, a different access digit is dialed at the substation A so that a one-way trunk circuit 141i connected to a four-digit remote exchange 1119 over a conductor 142 is seized, the substation D being v connected to the exchange 109 by a conductor 143. Incident to seizure of the one-way trunk circuit 14.0 one group of circuits is prepared therein Vfor repeating switch directing signals tothe exchange 109 and additional circuits are prepared for collecting and storing data pertaining to the ytoll callin a Vtrunk recorder 141 which is individually connected to the trunk circuit 140.

One `of the items Aof information which is collected and stored in conjunction with each toll call is the identiiication of `the calling substation A. In the automatic toll ticketing system shown and described `in detail in the above identified Morris et al. patent, calling party or line identication is provided by a vertilication technique in which the calling subscriber at the station A dials his own directory number immediately following the dialing of the access digit. In other Words, subscribers served by the exchange 107 are instructed that before they can use the toll trunking facilities to establish connections to the desired substations C and D served by the remote exchanges 108 and 109, they must dial their own directory numbers before dialing the directory numbers assigned to the desired called substations. In the present case, the calling subscriber at the substation A, after dialing the trunk selection or access digit, dials his own directory number into the trunk circuit 119. This trunk circuit repeats the impulses of each digit to the trunk recorder 125 and also repeats the impulses of each digit through a preselector 122 to verification switching equipment.

`More specifically, each impulse of each digit is discretely recorded as a mark pulse on a magnetic tape in the recorder 125. At the end of each digit, the trunk circuit 119 functions to transmit a space signal to the trunk recorder 125 which is likewise recorded on the recorder tape to indicate the end of the digit. Thus, groups of re corded markl pulses representing successive digits are separated on the tape by the space pulses recorded therebetween. v

Incident to seizure of the one-way trunk circuit `119 by the selector 114, the preselector 122 functions automatically to associate the trunk circuit with an idle one of a plurality of verification selectors. Assuming that a verification selector 123 is seized by the preselector 122 incident to seizure of the trunk circuit 119, the rst digit of the directory number assigned to the calling line 110,

`as repeated to the verification selector 123 through the preselector 122 from the trunk circuit 119, is utilized to move the wipers of this selector opposite the level of bank contacts in which are terminated the seizure trunks extending to the verification connectors of the group having access tothe line circuit multiples terminating the lines of theone hundred line group which includes the calling line 110. A preselector 144 performs the same funcitions as the preselector V122 for calls placed through the trunk circuit 140. During the interdigit pause between this digit and the second digit of the calling subscribers directory number, the selector 123 automatically and successively tests the switch trunks extending to the connectors until an idle connector is found. Assuming that a connector 124 is selected during this trunk hunting operation of the selector 123, the pulse repeating loop circuit from the trunk circuit 119 is switched through to the connector 124 by the selector 123 immediately after the wipers of this selector are positioned on the contacts terminating the seizure trunk of this connector. VThe Verification connector 124 responds to the second and third digits of the directory number assigned to the calling line 110 by successively selecting the subgroup of ten lines including the calling line and then the particular calling line itself. All that the Verification connector is called upon to do is to establish a through connection between the sleeve `lead path through the switches 123 and 124 and the sleeve lead path through the switches 113 and 114. In other words, a sleeve loop is established which extends from the trunk circuit 119 through the preselector 122, the verification selector 123, the verification connector 124, the line circuit multiple of the line 110, the finder 113, the selector 114, and the sleeve lead of the aol trunk 1719er backito the trunk circuit 11.9. If this path is successfully completed, the one-way trunk circuit 119 recognizes that the calling subscriber has properly identilied the line as the calling line. On the other hand, if this vsleeve loop is not completed, the trunk circuit 119 is informed that the calling line has not been properly identified.

At this point it may be noted that one of the features of the verification train is the provision of facilities in the `connector 124i (and in the other similar connectors) for answering back to the trunk circuit 119 to provide an indication `that the required number of digits has been dialed into the connector to set the wiper of this connector on the outlet contact individual to the subscriber line designated by thedirectory number which has been dialed into the trunk circuit. Thus, the trunk circuit 11% is informed by the connector 124 as to when the line identification test should be started. The verification train is dismissed immediately after the calling line verification test is completed regardless of whether this test is successful or not. Specifically, the trunk circuit 119, upon completing `the verication test, removes holding ground from the sleeve lead extending to the selector 123, with the result that this selector and connector 124 are released. Thus, these switches are made available for use by the other trunk circuits.

Assuming that the above described calling line verification test is not successful, the trunk circuit 119 refuses to establish a dial impulse repeating loop by way of the interofce trunk 12)v to the switching equipment in the remote exchange 108. Under such circumstances, the one-way trunk circuit 119 transmits a signal back over the calling loop circuit to indicate to the calling subscriber at the substation A that the call cannot be completed. It will thus be understood that unless the calling subscriber after dialing the single digit designating the group of trunks extending to the desired remote exchange correctly dials his own directory number, the trunk circuit 119 will not permit the connection to be extended to the called substation. The calling subscriber, upon receiving the described signal, is expected to release the connection. When this occurs, the line circuit 111 and link 112 are, of course, released. Also, in response to the on-hook signal received from the calling substation, the trunk circuit transmits an end-of-call signal, i.e. coincident mark and space pulses to the trunk recorder 125. Recording of these pulses without recording the other information which is always recorded incident to the successful completion of a call establishes that the call under consideration was unsuccessful so that it is disregarded during the .playback operation described below. In other Words, the

information recorded by the trunk recorder 125, being incomplete, is recognized as such by the playback facilities and is disregarded by these facilities so that no ticket is `printed for the call. After the end-of-call signal is transmitted to the recorder, the trunk circuit transmits several advance pulses to the recorder to advance the tape thereof in preparation for the recording of data pertaining to the next call handled by the trunk circuit 119.

-Following transmission of the advance pulses, the trunk circuit 119 is released.

Assuming now that the calling line verification test is successfully completed in the manner explained above, the trunk circuit 119 is automatically conditioned to repeat dial impulses by way of the trunk 120 to the automatic switching equipment in the remote exchange 108. The impulses of these digits are repeated by the trunk circuit 119 over the trunk 126 to the switching equipment in the exchange 108 with the result that this equipment functions to select the called line 21. These digits are also recorded in the trunk recorder 12S following the digits representing the directory number assigned to the calling line. Thus, after the dialing operation is completed at the calling substation, full information on the 7 identity of the calling and called lines is recorded in the trunk recorder 125.

Following the described operations, nothing further occurs in the trunk circuit 119 until the call is answered at the called substation C. In response to the call answering operation at the substation C, the trunk circuit 119 functions to associate the time pulse generating circuit 126 with the recorder 125 so that pulses equal in number t elapsed minutes are fed to the recorder 125 and recorded in the mark position along the tape of this recorder for the duration of the call. When the called subscriber at the substation C hangs up toconclude the call, nothing occurs except that the trunk circuit 119 functions to interrupt the transmission of time pulses from the time pulse generating circuit 126 -to the trunk recorder 125, thereby to terminate the call timing operation.

When the calling subscriber hangs up, the trunk circuit 119 opens the loop extending by way of the trunk 120 to the remote exchanger 108, with the result that the switching equipment in the exchange 108 occupied with the call is released. Coincident with this operation, the trunk circuit 119 removes holding ground from the sleeve lead of the trunk 119:1 for an interval long enough to effect release of the line circuit 111, the finder 113, and the selector 114, and then restores ground to this lead to guard the trunk circuit against seizure on another call before it has completed its recording operation. Substantially coincident with release of the line circuit 111 and the link 112, the trunk circuit 119 transmits a space pulse to the recorder 125 to mark the end of the elapsed time measuring operation, and then operatively associates a scanning circuit 228 with the trunk recorder 125.

.As a consequence, the scanning circuit 228, as controlled by the setting of a clock and calendar circuit 227, feeds pulses to the recorder 125 in decimal digit form which identify in succession the month, day, hour, and minute the call is terminated. The pulses making up the digits representing this information are recorded as mark pulses Yon the record tape of the recorder 125, and each digit is marked olf from its succeeding digit by the transmission of a space pulse to the trunk recorder from the trunk circuit 119 during the intervals separating the'digits.

After a full complement of time and data digits have been transmitted from the scanning circuit 228 to the trunk recorder 125 by way of the trunk circuit 119, the trunk circuit automatically records an end-of-call signal on the tape of the recorder. As explained above, this end-of-call signal is in the form of coincident mark and i space pulses recorded along opposite edges of the recording tape. After the end-of-call signal is recorded on the record tape of the recorder 125, the trunk circuit 119 automatically transmits live or six tape advance pulses to the recorder so that the record tape is` advanced an interval to space the coded information on the call just considered from the information recorded on the tape incident to the handling of a succeeding call by the trunk circuit 119. After the described tape advance operation is completed, the trunk circuit 119 removes guarding ground potential from the sleeve lead of the trunk 119e:

to render the trunk circuit accessible for use on other calls and otherwise restores itself to normal.

As will be understood from the above explanation, if the called line 121 served by the remote exchange 108 is busy at the time the described call is routed thereto or if the substation C is unattended so that the call is not answered, duration pulses and the described `time and date digits are not recorded on the record tape of the recorder 125. However, the end-of-call signal is recorded and the record tape is spaced following abandonment of the call at the calling substation in the same manner as in the case of a successfully completed call. Absence of the date, time, and elapsed time of call information from the record thus formed on the tape of the recorder 125 is recognized by the playback facilities which respond to this absence by refusing to print a ticket for the call.

The manner in which additional calls vareV handled by the trunk circuit 119 and information concerning these calls is recorded by the trunk recorder is exactly the same as explained above. Moreover, the other trunk circuits provided in the system and their respective associated trunk recorders operate in identical fashion to record information on calls to the remote exchanges 108 and 109 handled by these trunk circuits. It will be understood, therefore, that each trunk recorder may have recorded therein information on a large number of toll calls at the time the associated trunk circuit becomes operatively associated with the playback facilities under the control of a playback control circuit 230.

Under normal circumstances, the playback and ticket printing facilities are only rendered operative to convert the information stored in the trunk recorders into printed tickets on a periodic basis, say once during each twentyfour hour period. While these facilities are normally active, the plyback control circuit 230 functions sequentially to associate the trunk circuits with the translating and printing facilities. Referring now more particularly to the manner in which the playback operation is performed, it is pointed out that when the wipers of a sequence switch 231 in the playback control 230 are positioned on the contacts terminating the conductors extending to the trunk circuit 119, a busy test is rst performed in the playback control circuit to determine whether or not the trunk circuit 119 is engaged with a call. If this trunk circuit is occupied with a call, it tests busy to the playback control circuit 230 so that the sequence switch 231 of this control circuit is automatically advanced to the position corresponding to the next trunk circuit. Assuming that the trunk circuit 119 is idle at the time it is thus tested by the playback control circuit 230, the playback control circuit seizes the trunk circuit and thus operatively associates the trunk circuit with the translating and printing facilities. Incident to such seizure, guarding ground potential is applied to the sleeve lead of the trunk 119a in the circuit 230, thereby to guard the trunk circuit against seizure through the finder-selector links of the exchange 107. Coincident with this operation, separate pulse signal transmission paths are established through the trunk circuit 119 and the playback control circuit 230 between the mark and space heads of the trunk recorder 125 and the input terminals of two preamplier circuits 233e and 232. At the same time, a clutch drive magnet in the recorder 125 is energized through the trunk circuit 119 from the playback control circuit 230, thereby to establish a driving connection through which the record tape of the recorder 125 is driven forwardly back to its normal or start position. When the clutch magnet of the recorder 125 is en- Vergized in the manner indicated above, the tape of this recorder is driven inthe forward direction by the playback drive facilities. In this connection, the tape driving facilities include a common drive shaft and a common motor which are employed to drive the record tape of the trunk recorder during the playback operation thereof.

When the playback control circuit 230 seizes the trunk circuit 119 in the manner just explained, it also places marking ground potential upon a destination lead 10811 extending to a printing control circuit 235. This destination lead is provided to indicate operative association of the playback control circuit 230 with trunk circuits terminating those trunks which extend from the exchange 107 to the exchange 108. To this end, the destination lead 10811 is multiplied to those contacts of the sequence switch in the playback control circuit 230 which are engageable by the destination wiper of this sequence switch and correspond to trunk circuits terminating trunks extending from the exchange 107 to the exchange 108. In similar manner, a destination lead 10% is provided to indicate operative association of the playback facilities with trunk circuits terminating trunks extending from the exchange 107 to the exchange 109. Thus the destination lead 10951 is multipled to the contacts of the sequence facilities.

i `mark pulse ,clipping amplifier 233. In the amplifier 233,

gageable by the destination wiper of this switch and correspond to trunk circuits terminating trunks extendingA from the exchange 107 to the exchange 109.

When the destination lead tlSa is grounded in the playback control circuit 230 in the manner just explained, the printing control circuit 235 and a cost computer 239 are advised that the playback facilities are operatively associated with a trunk circuit terminating a trunk'extending from the exchange 107 to the exchange 198. Coincident with `grounding of the identified desstination lead, the playback control circuit functions to `reset all `of a plurality .of storage chains 238 to normal. The purpose of effecting a chain resetting operation at this time is that of clearing thel chains of any false registrations which may have been spuriously accumulatedV therein as a consequence of pulses developed at the output terminals of two amplifiers 233 and 234 incident to the switching of the input terminals of the amplifier circuits 233a and 232 from trunk circuit to trunk circuit by the sequence switch of the playback control circuit 230.

When the record tape in the recorder 125 is driven back to its start position, contacts are closed .in the recorder 125 to advise the trunk circuit 119 and the playback control circuit 23@ that the recorder 125 is now ready to release the information Vstored therein to the translating More specifically, when the indicated trunk recorder .contacts are closed, a` circuit is established for exciting an erase head in the recorder 125 from an erase supply source 229. Also incident to the closure of the identified contacts in the trunk recorder`125, thecontrol circuit 233 transfers control of the drive clutch magnet in the recorder 125 from itself to the printing control circuit 235. After these operations are completed, the equipment is fully conditioned to transfer the information stored or recorded on the record tape of the recorder 125 from this recorder to the storage chains 238.

The information recorded on the record tape of the recorder 125 is released to the playback facilities on a call-by-call basis. In thisregard, it will be recalled that the first record of a successfully completed call handled by the trunk circuit 119 which is recorded on the record tape of the recorder 125 comprises four successive digits, each containing from one to ten pulses, representing the directory number of the calling subscriber line 110, four successive digits representing the directory number of the called subscriber, a series of duration pulses designating the elapsed time of the call, a group of from one to twelve pulses designating the month, and a series of vsix digits of from one to ten pulses each designating the day, hour and minute that the call was completed. Each of the vdescribed digits, together with `the elapsed time pulses, are recorded as mark pulses onrthe record tape of the recorder 125 and the digits are separated by space pulses also recorded on the record element of the recorder 125. `Further, the last digit of the time-of-call data is followed by the described end-of-call signal.

During the record playback operation, the record ele ment in the recorder 125 is, of course, driven by the common drive facilities commonly associated-with `the group of trunk recorders including `the recorder 125. At the very start of this operation, an endof-call signal, i.e., coincident mark and space pulses, is first released by the trunk recorder 125. This signal is utilized in the printing control circuit 235 to effect certain control operation therein, including that of setting a steering circuit 237 so that the first set 4of mark pulses transmitted by the recorder 125 will be registered in the rst storage chain 238. As the mark pulses on the record tape of the recorder 125 are reproduced by the mark pulse head of this recorder, they are transmitted through the trunk circuit 119 and the playback control circuit 230 to the input terminals of the preamplifier circuit 233a. These pulses are amplified through the mark pulse preamplifier circuit 233e and impressed upon the input terminals of the the niark pulses are further amplified and clipped to uniform amplitude. These uniform amplitude pulses as they appear at the output terminals of the amplifier 233 are impressed uponthe input circuits of all of the storage or counting chains 238, but are only registered in the particular storage chain which A,has been conditioned to receive mark pulses by the steering circuit 237. Specifically, lthe first digit of the first-call recorded on the record tape of the recorder 1,25 is stored in the first storage chain 238, the second digit is stored in the second storage chain, and so on. The transfer `of the repeated mark pulses of different digits from storage chain to storage chain is effected by the steering circuit 237 in its response to space pulses received from the trunk recorder 125. More specifically, the space pulse recorded on the record element of the recorder are transmitted through the trunk circuit 119 and the playback control circuit 230 and are impressed `upon the input terminals of the preamplifier circuit 232. These pulses are amplified through the space pulse preamplifier circuits 232 and impressed upon the input terminals of the space pulse clipping amplifier 234. After amplification through the latter amplifier, the space pulses are impressed upon the steering circuit 237. Thesteering circuit responds to each space pulse transmitted thereto by effecting a storage chain transfer operation in the manner explained below. It will thus be understood that all of the digits, together with the elapsed time pulses, recorded on the record element of the recorder 125 as a result of the particular call under consideration, are successively stored in different ones of the storage chains 238. In this regard, it is noted that after the digits representative of the directory numbers assigned to the calling and called subscriber lines have been registered in the storage chains 238, the steering circuit 237 acts to condition the cost computer 239 to accept and register the elapsed time or duration pulses which are repeated to the playback facilities from the trunk recorder 125 immediately following the last digit of the directory number `assigned to the called subscriber line. The cost computer circuit 239 accepts these elapsed time pulsespbut when the next space pulse is received by the steering circuit 237, this circuit acts to disable the cost computer circuit 239 against accepting any further pulses. Incident to the receipt ofthe elapsed time pulses, the cost computer circuit 239, having previously been advised by the printing control circuit 235 as to the destination of the call, computes the cost of the call -to decimal code form.

When the next end-of-call signal, represented by coincident mark and space pulses, is received by the printing control circuit 235, this circuit is 'able to determine whether or not the call was successfully completed and hence whether or not a ticket should be printed on the call. If less than this number of groups of pulses is actually received and registered in the storage chains 238, the printing control circuit is instantly advised that the call was not successful and hence that no ticket should be printed. Under such circumstances, the printing control circuit' 235 immediately clears the storage chains 238, restores the steering circuit 237 to normal, and recloses the operating circuit for the drive clutch magnet in the trunk recorder 125 to initiate a new call playback operation.

As indicated above, when the end-ofcall signal is received by the printing control circuit 235, this circuit `immediately deenergizes the drive clutch magnet of the .ing operation is initiated immediately after the end-ofcall signal is received by the printingV control circuit 235. More specifically, when this signal is received, certain control relays in the printing control circuit 235 operate to initiate operation of a scanning switch which functions sequentially tro scan the storage chains 238 and the storage chains of the cost computer 239, and to transfer the information registered therein into permuta,- tion code form which is fed to the permutation magnets of a printer 236. Thus, each time a storage chain 23S is read, the permutation magnets of the printer- 236 are correspondingly excited, following which the printer prints the information registered in these magnets and then answers back to the scanning switch in the printing control circuit 235 advising this switch to take another step. The sequence of operations is repeated until all information registered in the storage chains 238 and the cost computer 239 is printed by the printer 236. Upon completion of the printing operation, the scanning switch of the printing control circuit 235 is automatically stepped to its home or normal position, the storage chains 238 are cleared or reset to normal, and the steering circuit 237 and 4cost computer circuit 239 are reset to normal. After these resetting operations are completed, the printing control circuit 235 recloses the operating circuit for the drive clutch magnet of the recorder 125 to restart movement of the record tape in the recorder 125 and thus initiate anew call playback operation.

The described call playback operations are repeated in the exact manner just described until the record tape in the recorder 125 has been cleared of all information recorded thereon. In this regard, it will be understood that immediately after the record tape passes by the combined recording and reproducing heads of the recorder 125, it passes by the erase head of this recorder so that the magnetic pulses impressed thereon are erased. Complete clearing of the record tape in the recorder 125 is indicated by movement of the tape back to its start position to effect reclosure of the start position contacts in the recorder. In response to this operation, the printing control circuit 235 measures off a predetermined time delay interval during which the drive clutch magnet of the recorder 125 is held energized to effect continued movement of the record tape in this recorder for a distance sufficient to permit recording of the date and time information of a very long call. After this delay interval is measured off, the printing control circuit 235 deenergizes the drive magnet f the recorder 125 to stop tape movement in the recorder, releases the trunk circuit 119, and effects advancement of the sequence switch 231 in the playback control cir-cuit 230 tot the setting corresponding to the next idle trunk circuit. Incident to the release of the trunk circuit 119, an end-of-call signal is recorded on the record tape to insure normalizing of the translating and printing facilities at the start of the next playback operation involving the trunk recorder 125. The end-of-call signal is followed by the usual tape advance operation. Also, incident to release of the trunk circuit 119, guarding ground potential is removed from the sleeve lead of the trunk 119e, thereby to render the trunk circuit accessible fto the selectors of the exchange 107.

As indicated above, the playback and ticket printing facilities are normally associated with the trunk circuits on a periodic basis and then are sequentially connected with-the trunk circuits through the step-byvep operation of the trunk circuit sequence switch 231 embodied in the playback control circuit 230. If for any reason, however, the recording capacity of any one of the trunk recorders should be nearly exhausted before the record tape thereof is cleared of information recorded thereon by the playback facilities in the manner just described, facilities are provided for immediately bringing the playback facilities into operative association with such a recorder. Thus, if this condition arises in the trunk recorder 125, for example, while a call through the trunk circuit 119 is in progress, the record tape of this recorder is advanced to close contacts in the recorder which results in operation of the trunk circuit 119 to prepare a circuit for applying ground potential to an emergency start conductor 230a and also to prepare a circuit for vmarking the trunk circuit as busy to the selectors having access Vthereto after the call in progress is terminated. These circuits are completed in the trunk circuit 119 when the call in progress is terminated and the switch train occupied with the call is released. Grounding of the lead 23061 in the trunk circuit 119 has the effect of causing the playback control circuit 231! to associate the playback facilities with the trunk circuit 119 immediately after the playback operation, which may be in progress at the time the lead 231m is grounded, is completed. In other words, grounding of the lead 230e results in the setting up of preferential circuits which cause an interruption in the normal sequential association of the playback facilities with the trunk circuits and an immediate association of these facilities with the trunk circuit 119. Once the playback facilities are operatively associated with the trunk circuit 119, the playback operation required to clear the recorder of the information stored therein is carried out in the exact manner explained above. In this regard, it will be understood that once the trunk recorder 125 is cleared of the information stored therein and the trunk circuit 119 is restored to normal, ground potential is removed from the lead 235g.

As indicated above, the playback control circuit 230 as controlled by the printing control circuit 235 is provided with apparatus for energizing an alarm device 244 to bring in a major alarm in the event of a failure in the system. Such failure may be caused by defective tubes, wiring failures, failure of the recording and reproducing heads of a trunk recorder, etc. The arrangement is such that if no successfully completed calls are evidenced to the translating and printing facilities during playback of any one of the trunk recorder tapes, the printing control circuit 235 transmits a signal to this effect to the playback control circuit. The latter circuit upon receiving this signal stops operating, locks up and energizes the alarm device 244 to signal the exchange attendant that trouble exists.

Trunk Recorder 125 The trunk recorder 125, in which the selected toll call data including the duration information is stored during the extension of a call and from which this data is transmitted during a playback operation, is shown in fragmentary schematic form in FIG. 3 of the drawings. This trunk recorder preferably is of the type shown and described in detail in United States Patent No. 2,867,435 to Howard S. Gleason. As illustrated, the trunk recorder 125 includes an endless loop of magnetic tape or film 300 adjacent to transversely disposed portions of which are disposed a mark pulse transducing head 302 and a space pulse transducing head 304. The transversely spaced disposition of these two transducing heads forms two separate data channelsfon the magnetic tape 300 for receiving mark and space pulse information. As described above, intelligence is stored on the tape 300 by providing a number of mark pulses equal to or proportional to the value of a digit to be entered, and space pulses are recorded on the tape between adjacent groups of mark pulses to separate successive digital entries. Further, a control or end-of-call signal comprising simultaneously recorded mark and space pulses is provided to indicate the end of the recorded data pertaining to a single toll call. The trunk recorder 125 further includes an erase transducing head (not shown) having an erasing gap effective over the entire transverse area of the tape 300, the erasing head being rendered effective during the playback operations to erase the previously transmitted information and thus condition the tape 354B for receiving the next items to be stored thereon.

The magnetic tape 300 in the trunk recorder 125 is advanced stepby-step following the recording of each mark or space pulse during information storing or recording operations` and, to accomplish this, the trunk` recorder includes a step-by-step drive mechanism actuated by an i t 13 l s advance magnet 3416. A resiliently and downwardly biased pinch roller 308 is disposed adjacent vone surface of the magnetic tape 30]@ and a commontcapstan 316 is disposed in engagement with the opposite surface f the tape 300 immediately opposite the pinch roller- S; To provide a means for `rotating the ,capstan 310 .through short increments in a .step-by-step manner during recording` operations,a ratchet 312 `is secured tothe capstan 319 by a shaft 314. The advance magnet 306 vis provided with a pivotally mounted armature 316 to which is connected a tension spring 31S. When the advance magnet 396 is energized to move the armature 3.16 downwardly, a pawl 320 carried on the armature 316 engages a tooth on the ratchet wheel 312 androtates the wheel 312 and the connected capstan 31,9 through a predetermined angular movement. This-advances the magnetic tape 31tbftoa position for receiving the next impulse to be stored there- As indicated above, the magnetic tape 30d in the trunk recorder 125 is advanced continuously during the transmission of the data pertaining to each call,v this transmission being momentarily arrested while the previously transmitted data is recorded by the printer 236. To provide a continuous drive mechanism in the trunk recorder 125, a driven wheel 322 is secured to the shaft 314. A continuously energized motor 324 which is connected to a drive roller 326 provides a prime mover for rotating the driven wheel `322 and the capstan 310 secured thereto. To selectively render the continuous drive mechanism effective, a clutch magnet 328"is provided. A pivotally mounted armature 330 of the clutch magnet 328 forms a stop memberwhich is normally urged up- Wardly by a tension spring 332 so that an end portion 330a thereof engages a detent 33,4 carried on a pivotally `mounted lever 336.` A tension spring 338 tends to pivot the lever 336 in a clockwise direction, as shown in FIG. 3, but this clockwise rotation'is prevented by the engagement of the stop 334 and the detent portion 330e of the armature 33t). When the clutch magnet 328 is energized to pivot its armature 33t) downwardly or in a counterclockwise direction, the detent portion 339e thereof moves out of engagement with the stop 334 so that the spring 33S pivots the lever 336 in a clockwise direction to move an idler roller 339, which is rotatably mounted .on the lever 336, into a position interposed between the drive roller 326 and the Vdriven wheels 332, thereby placing the capstan 310 in rotation to continuously .advance the magnetic tape 399. When the clutch magnet 323 is released, the spring 332 moves the armature 330 upwardly or in a clockwise direction so that the detent portion 33de of the armature 330 engages the stop 334 to move the idler roller 339 out ,of driving engagement with the drive roller 326.

In addition to the components of the trunk recorder 125 which are indicated schematically in `FIG. 3, this trunk recorder also includes a-sensing arrangement controlled by conductive portions vcarried on one surface of the tape 300 for indicating the effective beginning or home position of this tape. The trunk recorder mechanism 125 may also include a contact arrangement controlled by the clutch magnet for interrupting thej operating circuit for the advance magnet 396, thereby to prevent operation of the pawl and ratchet type drive mechanism during the operation of the continuous drive mechanism.

Recording Duration Information in the Trunk Recorder 125 A set forth above, incident to the collection and storage of the items of information pertaining to each toll call, a group of pulses equal in number to the number FIG. 3 illustrates, in a fragmentary manner, some of the components in the trunk circuit 119 which are utilized during the recording of duration linformation in the trunk recorder 125. Y

More specifically, in response to the receipt of answering supervisory signals from a called substation, such as the substation C, a supervisory slave relay 355 is operated to close Va plurality of contacts 356 and 357, among others. The closure of these two contacts prepares circuits for supplying mark pulses to the mark `pulse transducing head 302 in the trunk recorder 125 and for periodically operating the advance magnet 306 therein. More specically, the closure of the contacts 35.6 connects the time pulse generating circuit`2'26, which is common to a plurality of trunk circuits .similar to the trunk `circuit 119, with the operating winding of the mark pulse transducing head 362 through a pair of normally closed contacts 341. The time pulse generating circuit 226 provides grounded battery signals over the circuit including the closed contacts 356 and 341 at one minute intervals so that a mark pulse is recorded on the magnetic tape 3.96 at the end of .each one-minute interval during the maintenance of an extended connection between a calling and a called subscriber. If desired, the generating circuit 226 could provide ground impulses and the winding of the transducing head 302 could be connected to grounded battery rather than ground. The closure of the contacts 357 connects the operating winding of a common pulse repeater relay 345 to the time pulse generating circuit 226 to prepare a circuit for operating the relay 345 immediately following the transmission of each grounded battery impulse to the mark pulse transducing head 302. In response to the transmission of each ground impulse through the closed contacts 357 to the common pulse repeater relay 345, a pair of contacts 346 are momentarily closed to cause the momentary operation of the advance magnet 306 in the trunk recorder 125. The periodic energization of the magnet 396 advances .the magnetic tape 300 a single step immediately following the recording of each mark pulse thereon.

At the termination of the call, the supervisory slave relay 355 is released incident to the release of .the connection so as to open the contacts 356 and 357, among others. The opening of the contacts 356 interrupts the above described path for supplying mark pulses for storage on the magnetic tape 300, and the opening of the contacts 357 interrupts the above described path for causing periodic operation of the advance magnet 396 in the trunk recorder 125. It will be noted that the time pulse generating circuit 226 is common to a plurality of trunk circuits similar to the circuit 119, and, accordingly, the generating circuit 226 is in continuous operation to Aprovide mark pulses and advance magnet operating signals at Vthe end of each one-minute interval. The supervisory relay in any selected trunk circuit, such as the circuit 119, is operated immediately upon the receipt of answering supervisory signals. These signals may be received at any time during the cycle of operation of the generating circuit 225, and, accordingly, a mark pulse representing an elapsed time of one full minute may be recorded on the magnetic tape 300A of the trunk recorder following an actual elapsed time of merely a few seconds. However, means are provided in the cost computer 239 for insuring that the monetary charge to be assessed for each of these calls is not affected by the varying periods of time at which the first mark pulse is recorded on the magnetic tape 300.

Playback Operation including the trunk recorder 125, are to be played back or transmitted to control the operation of the printer 236,

the playback control circuit 230 (FIG. 3.) is placed in operation to advance the stepping Vswitch 231 over its contacts to search for and seize each of the idle trunk circuits and its associated .trunk recorder. The switch 231 includes a plurality of wipers 231a-231f which are advanced step-by-step so that a busy test is performed over a wiper 231:1 under the control of a switch relay 353 provided in the playback control circuit 230. When an idle trunk circuit, such as the circuit 119, is encountered during stepping operation, further movement of the switch 231 is arrested with the Wipers 231a-231f in engagement with the contacts individual to the trunk circuit 119.

To prepare the trunk recorder 125 for transmitting information to the registers associated with the printer 236, the wiper 23112 completes an operating circuit for a playback switch relay 340 in the trunk circuit 119, thereby voperating this relay to open the contacts 341 and 344 and to close a plurality of contacts 342 and 343, among others. The opening of the contacts 341 disconnects the mark pulse transducing head 302 from the pulse generating circuits controlled by the trunk circuit 119, which are utilized during data recording operations, and the concurrent closure of the contacts 342 connects the winding of the transducing head 302 to the input of the mark pulse amplifiers 233a and 233 through the wiper 231i of the stepping switch 231. The completion of this path prepares the head 302 for reproducing mark signals for transmission through the mark pulse amplifiers 233g and 233 to an output mark pulse conductor 354 which is common to all of the storage chains 238 and also to the cost computer 239. Therefore, when the magnetic tape 300 is advanced to induce signals in the transducing head 302, these signals are amplified and clipped and are extended to the inputs of all of the storage devices in the playback facilities by the common mark pulse conductor 354.

The opening of the contacts 344 and the closure of the contacts 343 disconnect the space pulse head 304 from local control circuits in the trunk circuit 119 and connect the winding of the head 304 to the input of the space pulse amplifiers 232 and 234 through the wiper 231e of the stepping switch 231. Accordingly, when the magnetic tape 300 in the trunk recorder 125 is advanced, the space pulses induced in the head 304 are amplified and clipped in the circuit components 232 and 234 and supplied to the steering circuit 237. As described in detail in the above identified Morris et al. patent, the steering circuit 237 sequentially supplies enabling potentials to the input or drive tubes in the plurality of storage chains 238 and in the cost computer 239 so that the various groups of mark pulses appearing on the common mark pulse conduetor 354 are rendered effective in sequence to control the operation of only a single one of the storage chains.

Returning now to the operation of the stepping switch 231 incident to seizure o-f the trunk circuit 119, the movement of the wiper 23117 into engagement with the contact associated with the trunk circuit 119 completes a circuit for providing the printing control circuit 235 and the cost computer 239 with information relating to the designation of the called exchange 108 and the rate structure to be utilized in assessing monetary charges for calls extended to this exchange. More specifically, the ground supplied to the wiper 231d is extended to a first destination or rate relay 360 in a destination relay circuit 367, thereby operating this relayto close a plurality of contacts 361, 362, and 363, among others. The rate infor mation provided by the operation of the relay 360 comprises a base time period for which an initial charge is :assessed and an overtime interval for each of which a cost increment is to be added to the initial charge. Since the destination or rate relayV 360 is operated in response to seizure of the trunk circuit 119 andsince the trunk recorder 125 associated with this trunk circuit stores data pertaining to calls extended only to the remote exchange 108, the relay 360 remains operated during the entire period that the trunk circuit 119 is seized to provide unilidentified Morris et al. patent.

16 form rate information to the cost computer 239 for use in establishing charges for each of the individual calls whose data is stored on the magnetic-tape 300.

As an illustration, it is assumed thatan initial charge of ten cents is to be assessedffor a call having a base time period equal to or less than three minutes and that an additional cost increment of five cents is to be assessed for each additional overtime interval of one minute. The information relating to the base time interval is supplied by the closure of the contacts 361 to ground a conductor 793 which extends to the cost computer 239 through a cable 36S. The information relating to the initial charge of ten cents is provided byV closing the contacts 362 and 363 to connect resistance B-lpotential to a pair of conductors 1091 and 1093 which extend tov the computer 239 over the cable 368. The B-lpotential applied to the conductor 1091 represents a units cents digit of 0 and is utilized to prime the computer 239 to a units cents manifestation of 0. Similarly, the B+ potential connected to the conductor 1093 represents a tens cents digit l and primes the cost computer 239 to provide a manifestation of this digit.

In the event that the trunk circuit 140 extending to the remote exchange 109 in which the called substation D is located is seized by the playback control circuit 230, the wiper 231b operates a second destination or rate relay 370 to close a plurality of contacts 371, 372, and 373. Assuming that the rate structure applicable to calls to the remote exchange 109 comprises a base time period of three minutes for which an initial charge of twenty-iive cents is to be made and that an additional charge of five cents is to be made for each additional minute of overtime, the closure of the contacts 372 and 373 applies B+ potential to a plurality of conductors 1092 and 1094 extending to the computer 239 through the cable 368 representing the units cents digit l5 and the tens cents digit 2, respectively. The closure of the contacts 3'71 applies ground to the conductor 793 to prime the computer 239 With the three-minute base time period information.

Referring back to the seizure of the trunk circuit 119 by the playback control circuit 230, the wiper 231C prepares a path for initiating movement of the magnetic tape 300 in the trunk recorder so that the data stored thereon is transmitted tothe data storing and printing facilities through the amplifiers 232, 233, 233:1, and 234. This circuit is selectively controlled by a relay 380 in the printing control circuit 235. Following the completion of the seizure of the trunk circuit 119 and its associated trunk recorder 125, the printing control circuit 235 operates the relay 380 to close a pair of contacts 381, among others, in the manner described in detail in the above This ground is extended over the wiper 231C to operate the clutch magnet 328 so that the detent portion 330:1 of the armature 330 is displaced to permit the idler roller 339 to be interposed between the driving roller 326 and the driven wheel 322. The completion of this operative drive places the capstan 310 in continuous rotation Iso that the magnetic tape 300 is advanced to initiate the transmission of mark and space pulse information.

As described above, the first item of information stored on the tape 300 is the preliminary end-of-call signal comprising simultaneous mark and space pulses which are transmitted through the amplifiers 232, 233, 233er, and 234 to the printing contro-l circuit 235 and utilized therein to restore all of the 'storage chains 238 and the cost computer 239 to a normal condition, thereby removing any abnormal registrations which may have been provided incident to the seizure of the trunk circuit 119. The transmission and receipt of the preliminary endof-call signal releases the relay 380 to open the contacts 381 so that the magnetic tape 300 is not advanced during the resetting operation. Upon completion of the resetting operation, the contacts 331 are again closed to cause the transmission of the items of information pertaining to the 17. first toll call from the trunk recorder 125 to the storage chains 238.

As described above,Y the steering circuit 237 is operated by the transmitted space pulses to sequentially render the plurality of storage chains 238 eiective to receive and store the items of information pertaining to the first call represented by the transmitted groups of mark pulses provided on the common mark pulse conductor 354. Following the storage ofthe calling and called station designation, thespace pulse immediately preceding the group of mark pulses representing the duration of the toll call operates the steering circuit 237 to remove the enabling potential from the input or drive tube in the preceding storage chain 238 and to apply a positive enabling potential to a conductor 237e which extends to the input of an elapsed time counter 600 forming apart of the cost computer 239. This enabling potential renders the elapsed time counter 600 and the remainder of the cost computer 239 responsive to the group of duration pulses next to be transmitted from the trunk recorder 125.

Elapsed T me Counter 600 The elapsed time counter 650 (FIGS. 4, 5, and 6) is operated by the group of mark pulses representing call duration to provide an electronic manifestation or registration of the duration of the toll call. To vthis end, 'the elapsed time counter 60) is provided with a units minutes counting ring 500 and a tens minutes counting chain 4in) comprising progressively advanced counting circuits of the type shown and described in detail in the above identilied patent to Frank A. Morris et al.

The input of the units minutes counting ring 50G is connected to the mark pulse conductor 354 so that the group of duration mark pulses sequentially .advances this ring in accordance with the number of mark pulses therein. This group of mark pulses contains a plurality of discrete pulses equal in number to the minutes of the duration of a particular toll call. In addition, the output of the ring 550 is interconnected with the input of the tens minutes counting chain 40@ so that this counting chain is advanced a single step in response to each complete cycle of operation of the units minutes counting ring 590.

The units minutes counting ring 56) includes a drive tube 55), a normally conductive prime tube 550 representing 0, and a plurality of counting tubes 5'7,'6l@, 620, 630, 640, 650, 660, 670, and 680 representing the digits l-9, respectively. The control electrodes of each of the counting tubes and the prime tube are provided with a normal operating potential by a voltage divider 383 in the printing control circuit 235 which is connected to these starting or control electrodes by a conductor 3&4 which extends to the eiapsed time counter 609 through the cable 36d. The anode of each of the counting tubes and the prime tube is connected to the starting electrode of the next succeeding tube in the counting ring by a coupling condenser similar to a condenser 567 connecting the anode of the prime tube 560 with the control electrode of the 1 manifesting tube 57. The anodes of each of the counting tubes and the prime tube 'are connected to a suitable source of B-I- potential through individual anode resistors, similar to a resistor 564 provided in the anodev circuit of the prime tube 561i. The cathodes of all of the counting tubes are connected to ground through a common cathode resistor 563 in the cathode circuit of the prime tube 560 over a circuit including a conductor 561 and a pair of normally closed contacts 391 controlled by a reset relay 390 in the printing control circuit 235, the conductor 551 extending be; tween the elapsed time counter (willi and the printing control circuit 235 through the cable 35S. Since the prime tube 56d is normally in a conductive condition, a positive potential is normally applied to the cathodes of all of the counting tubes in the units minutes counting ring 500.

As described above, when the elapsed counter 600 is rendered responsive to receive the group of duration mark pulses, a positive enabling potential is connected to the conductor 23751 by the steering circuit 237, and this .potential is extended to the control electrode of the drive tube 55@ to render this tube responsive to applied mark pulses. Accordingly, when the first mark puise in the group of pulses representing the duration of a toll call is applied to the common mark pulse conductor 354, this pulseis coupled through a condenser 554 to fire the drive tube 551B. in being rendered conductive, the tube 55d produces a relatively large voltage drop across a cathode resistor 552 of relatively large magnitude so that charging current for a condenser 553 liows from ground through the common cathode resistor 563 to raise the potential of the cathode of the prime tube 55) and of the cathodes of all of the counting tubes in the units minutes ring 50d. The prime tube 565, which is in a conductive condition, is extinguishedby the increased positive potential provided across the common cathode resistor 563 inasmuch as this voltage drop together with the potential drop across its anode resistor 564 is such that conduction can no longer be sustained.

The anode of the drive tube 550 is connected directly to B-ipotential so that, upon being rendered conductive, the large value of its cathode resistor 552, by reducing the eective potential applied across the tube 55% or by reducing the current iloW therethrough necessary to maintain ionization, extinguishes the drive tube 55d) by relaxation to permit this tube to be again rendered conductive under the control of the next mark pulse applied through the condenser 554. The termination of the charging current for the condenser 553 reduces the voltage drop across the common cathode resistor 563 to a point such that, when the tube 560 is extinguished, as described above, a positive pulse is coupled through the condenser 557 to the starting or control electrode of the l manifesting tube 570, this tube is rendered conductive to manifest a units minutes digit l representing the receipt of a single mark pulse by the units minutes counting ring 560. In a similar manner, the tubes 616, 620, 63S), 645, 650, 654i, 670, and 680 are sequentially rendered conductive under the control of additional mark pulses applied to the control electrode of the drive tube 55).

When the tenth mark pulse in a given group of duration pulses is applied to the drivetube 550, the 9 manifesting tube 68) is extinguished to provide a positive going pulse at Ae anode thereof forcontrolling step-by-step operation of the `tens minutes counting chain 408 and for firing the prime tube 555, which manifests 0. More specifically, when the 9 manifesting tube 639 is extinguished, a positive pulse is coupled through a condenser 556 to the control electrode of the 0 manifesting tube 564), thereby rendering this tube conductive. Accordingly, ift response to the application of each ten mark pulses, the units minutes counting ring 590 is advanced through ya single cycle of operation.

The tens minutes counting chain 400 comprises a drive tube 419, a normally conductive prime or 0 manifesting tube 42), and a plurality of cold cathode counting tubes 439, 440, 450, 460, 470, 480, 510, 520, and 530 representing the tens minutes digits 1-9, respectively. The circuitry and the operation of the chain 400 is similar to the ring Stit and, accordingly, is not described in detail. The cathodes of the plurality of counting tubes are connected to a common cathode resistor in the cathode circuit of the prime tube 420 by a pair of normally closed contacts 392 and a conductor 421 which extends to the printing control circuit 235 through the cable 368. Also,

the control electrodes of the prime tube 420 and of the through a condenser 415 to the control electrode of the drive tube 410. This control electrode is provided with a fixed bias so that the drive tube 410 is momentarily fired by each pulse supplied by the ringV 50@ to advance the chain 40) a single step. The sequential application of positive pulses to the control electrode of the drive tube 410 under the control of each cycle of operation of the units minutes counting ring 59% produces a sequential energization of the tubes comprising the counting chain 400 so that, at any particular given time, a conductive tube in the units minutes counting ring 550 and a conductive tube in the tens minutes counting chain 400 electronically manifest the total of the number of pulses received from the mark pulse conductor 354 representing the duration of the toll call in minutes.

In order to make the information electronically manifested or registered in the elapsed time counter 600 available to the printing control circuit 235, the output anodes of the tubes in the units minutes counting rings Sil() are interconnected with like designated contacts in a selected stepping position of a stepping switch 399 in the printing control circuit 235 by a plurality of conductors 565 and 515 which extend to the printing control circuit 235 through a cable 685. The output anodes of the plurality of tubes in the tens minutes counting chain 460 are connected to like designated contacts forming another stepping position of the stepping switch 399 by a plurality of conductors 491 and 511 which extend to the printing control circuit 235 through the cable 655.

The information electronically registered or manifested in the elapsed time counter 600 is utilized by the printing control circuit 235 by operating control elements associated with the printer 236 in accordance with the iiow of current through'the tubes selectively rendered conductive. In order to provide an increased flow of current through the conductive tubes, the printing control circuit 235, when it is desired to initiate the production of a printed toil ticket, operates a second prepare-to-read relay 395 which closes a plurality of contacts 3% and 397, among others, to connect the commonly connected cathodes of the plurality of counting tubes in the units minutes counting ring 500 and in the tens minutes counting chain 00 directly to ground, thereby resulting in an increased flow of current through the conductive tubes.

In addition to grounding the commonly connected cathodes of the tubes forming the counting chain 400 and the counting ring 569, when data is to be recorded, the printing control circuit 235 operates a prepare-to-read relay 335 to close a plurality of contacts 386 and 387, among others. The closure of the contacts 387 applies ground to a conductor 413 which is connected to the control electrode of the drive tube 410 in the counting chain 4%. The ground applied to the control electrode of this tube renders the drive tube di@ insensitive to spurious voltages which may be coupled thereto and, accordingly, prevents the drive tube 410 from operating during the time that the information manifested in the chain 450 is being utilized by the printer 235 to prevent any possibility of producing a false indication of the value of the tens minutes digit. The closure of the contacts 386 connects a low resistance shunt across a portion ofthe potentiometer 383 to reduce the biasing potential applied to the control electrodes of the tubes inthe circuits 45t) and 50i) to render these tubes insensitive to spurious voltages which may be provided incident to the data recording operation.

Following the production of a printed ticket including the items registered in the storage chains 238, the printing control circuit 235 releases the prepare-to-read relays 385 and 395 and operates a reset relay 390, thereby to condition the elapsed time counter etltlfor another cycle of operation under the control of. the next group of mark pulses representing the duration of the next succeeding call. The release-of the relay 385 opens the contacts 386 to increase the biasing potential supplied to the counting 20 tubes in the chain 400 and the ring 590 and opens the contacts 387 to remove ground from the control electrode of the vdrive tube 410 in the` chain 49); The release of the relay 395 opens the contacts 396 and 397 to disconnect direct ground from the cathodes of the counting tubes in the chain 496 and the ring 550. The operation of the reset relay 390 opens the contacts 391 and 392 to disconnect the commonly connected cathodes-of the tubes representing l-9 in both the units minutes counting ring 560 and the tens units counting chain 400 from the common cathode resistors Vtherein so that Vthe conductive tubes are extinguished.

In addition, the operation of the reset relay 390 closes a pair of contacts 393 to apply a positive'biasing potential to a conductor 461 which is connected to the control electrodes of the prime tubes 420 and 569. The application of this biasing voltage renders these two prime tubes conductive so that, prior to the receipt of the next group of duration pulses on the conductor 354, the tens mmutes counting chain 400 and the units minutes counting ring 569 are reset to a normal operating condition representing an elapsed time of 00 minutes'. The firing of the prime tubes 42d and 560 does not vary the non-conductive state of the remainder of the tubes forming the counting chain 4G@ and the counting ring 500 inasmuch as the cathodes of the counting tubes are disconnected from the cathode resistors controlled by the prime tubes. Following a predetermined interval of time, the reset relay 350 in the printing control circuit 235 is released to reestablish the conductive paths provided by the conductors 421 and 551 so that the cathodes of the counting tubes are connected to the common cathode resistors in the cathode circuits of the prime tubes 424i and Sell. The release of the reset relay 390 also removes the positive biasing Voltage from the conductor eiland thereby conditions the elapsed time counter dit) for operation under the control of the next group of mark pulses representing the duration of the next succeeding toll call.

Accordingly, the printing control circuit 235, following theproduction of a permanent record containing the items of information pertaining to a particular toll call, conditions the elapsed time counter 600 to receive the items of information pertaining to the next toll call. This resetting operation is accomplished by opening the leads 421 and 561 so that all of the counting tubes in the counting chain 456 and counting ring 500 are extinguished. Further, the resetting operation of the printing control circuit 235 places a positive bias on the control electrodes of the two prime tubes 42) and 560 so that these tubes are primed conductive to manifest an elapsed time of 00,

In summary, the elapsed time counter 600 is rendered effective under the control of the steering circuit 237 to receive the group of mark pulses on the mark pulse conductor 35d pertaining to the duration of a particular toll call. These received mark pulses sequentially advance the counting ring 500 and, if the duration of the call exceeds nine minutes, also advance the tens minutes counting chain 490. At the end of the group of mark pulses, a single tube is conducting in both the tens minutes counting chain 4% and the units minutes counting ring 50i) to produce an electronic manifestation or registration of the total number of minutes of elapsed time in a particular toll call. The information provided by the electronic manifestation of the duration of the toll call produced by the elapsed time counter 600 is connected to the printer 236 by the stepping switch 399 in the printing control circuit 235 and utilized to produce a toll ticket providing a permanent record of the duration of this particular toll call.

The elapsed time counter 600 is conditioned for transmitting the registered information and is also reset under the control of the printing control circuit 235 so that, in a normal operating condition, the 0 manifesting tube 560 in the units minutes counting ring 505 and the 0 mani- 

1. IN A COMPUTING DEVICE FOR DETERMINING THE TOTAL CHRAGE FOR A VARIABLE NUMBER OF UNITS, WHEREIN THERE IS A FIRST GIVEN CHARGE FOR ANY NUMBER OF UNITS UP TO A PREDETERMINED NUMBER OF BASE UNITS AND A SECOND GIVEN CHARGE FOR EACH UNIT IN EXCESS OF SAID PREDETERMINED NUMBER OF BASE UNITS, SAID DEVICE COMPRISING REGISTER MEANS FOR STORING SAID VARIABLE NUMBER OF UNITS AS A SERIES OF SIGNALS EQUAL IN NUMBER TO THE NUMBER OF UNITS STORED, NORMALLY CLOSED GATING MEANS, A NORMALLY ENABLED BASE UNIT COUNTER, A CHARGE COUNTER, MEANS FOR PRIMING SAID CHARGE COUNTER TO A COUNT MANIFESTING SAID FIRST GIVEN CHARGE, MEANS COUPLED BETWEEN SAID REGISTER AND SAID BASE UNIT COUNTER FOR SEQUENTIALLY ADVANCING THE COUNT OF SAID BASE UNIT COUNTER IN RESPONSE TO EACH STORED UNIT, MEANS COUPLING SAID BASE UNIT COUNTER TO SAID GATING MEANS FOR OPENING SAID GATING MEANS IN RESPONSE TO THE COUNT OF SAID BASE UNIT COUNTER HAVING BEEN ADVANCED BY SAID PREDETERMINED NUMBER OF STORED UNITS AND FOR DISABLING SAID BASE UNIT COUNTER IN RESPONSE TO THE OPENING OF SAID GATING MEANS, AND MEANS INCLUDING SAID GATING MEANS COUPLED TO SAID CHARGE COUNTER AND SAID REGISTER FOR SEQUENTIALLY ADVANCING THE COUNT OF SAID CHARGE COUNTER BY AN AMOUNT EQUAL TO SAID SECOND GIVEN CHARGE ONLY WHEN SAID GATING MEANS IS OPENED IN RESPONSE TO EACH STORED UNIT IN EXCESS OF SAID PREDETERMINED NUMBER OF BASE UNITS. 